The invention relates to an electronic component having a corrosion-protected bonding connection and to a method for producing the same. For this purpose, the electronic component has at least one semiconductor chip on a substrate. Furthermore, a bonding connection at risk of corrosion is provided on the semiconductor chip. As an encapsulation of the at least one semiconductor chip and the at least one bonding connection at risk of corrosion, they are surrounded by a hermetically enclosing package.
The document DE 10 2008 024 599 A1 discloses in this respect packaged active microstructures with direct contacting to a substrate. For this purpose, a microstructured component has active microcomponents, a substrate and semiconductor circuits. Arranged on the substrate is at least one package with one or more active microstructures arranged therein, at least one of the active structures being brought into electrical contact with an electrical conductor track of the substrate through the package surrounding it.
For this purpose, the package consists of a bottom element and a top element, between which the active structures are located, the bottom element being connected to the top element by way of a sealing frame. The bottom element and/or the top element may have depressions, arranged in which there is a getter material, which, when activated, takes up gas molecules in a definable way and thereby changes the gas atmosphere in the package. The getter material may serve the purpose of absorbing moisture or capturing particles. The contact points with respect to the semiconductor circuits may be bonding areas.
The document DE 196 03 746 A1 discloses an electroluminescent layer system, which has within the layer system a getter layer of a getter metal or of a hygroscopic polymer. The hygroscopic polymer has a mixture of a binder polymer and a powdered hygroscopic substance. The getter layer ensures that no residues of oxygen and/or water can get to the electroluminescent layer system.
The conditions in the case of an electronic component that has an interior space or cavity in a package in which unencapsulated semiconductor components are arranged on a substrate and in which bonding wire connections on a semiconductor chip are exposed to the atmosphere of this interior space or cavity are not comparable with a densely packed layer system, in particular if the hermetically closed-off package is intended to provide protection for gold-aluminum thin-wire bonding connections, which are neither present nor to be protected in the layer system.
On the other hand, it is known that, when silicones are used inside a hermetically enclosing package, at relatively high temperatures water can be produced if precautions involving protective gas are not taken. In combination with extremely small amounts of halides, the water can form an electrolyte, which contributes to the corrosion of gold-aluminum phases in gold-aluminum thin-wire bonding connections, and can consequently lead to the premature failure of such bonding wire connections, which reduces the service life of the electronic component. In such cases, hermetically closed-off electronic packages are also filled in a gastight manner with protective gas in the form of helium or nitrogen, in order to slow down the corrosion process, and consequently increase the service life of such electronic components.
In addition, layers of getter metal may be provided in hermetic packages for the adsorption of reactive gases, suitable getter metals such as for example calcium, lithium or strontium being known from the document DE 196 03 746 A1. Such getter materials themselves or the provision thereof in getter layers by vapor deposition, sputtering or thermal activation are relatively expensive and are also relatively complicated to handle. A further alternative for providing corrosion-protected bonding connections is to apply noble-metal-containing protective layers to the aluminum metal alloys of the semiconductor chip.